package thread;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * 线程池
 * 线程池是线程的管理机制 主要解决两方面问题
 */
public class ThreadPoolDemo {
    public static void main(String[] args) {

        ExecutorService threadPool = Executors.newFixedThreadPool(3);

        for (int i = 0 ; i < 5 ; i++){
            Runnable r = new Runnable() {
                @Override
                public void run() {
                    try {
                        Thread t = Thread.currentThread();
                        System.out.println(t.getName() + ":正在执行一个任务...");
                        Thread.sleep(5000);
                        System.out.println(t.getName() + ":任务执行完毕!");
                    } catch (InterruptedException e){
                        e.printStackTrace();
                    }
                }
            };
            threadPool.execute(r);
            System.out.println("将一个任务交给线程池执行...");
        }

        //threadPool.shutdown();  //不会立刻停止 等程序执行完毕后在停止
        threadPool.shutdownNow(); // 关闭线程池
        System.out.println("线程池关闭...");
    }
}
